Table 2.

IC₅₀ values of reference standards.

Reference Standard	DPPH· 1 IC50 (μg/mL)
quercetin (≥95%)	5.5 ± 0.3
quercetin 3-O-β-d-glucopyranoside (≥90%)	11.0 ± 1.0
rutin (≥95%)	13.9 ± 0.7
Trolox (≥97%)	6.1 ± 0.4
chicoric acid (≥95%)	9.7 ± 1.7

¹ IC₅₀ values calculated by linear regression of % scavenging and logarithmic concentration.